Fine Tuning

The biggest problem I've had with making our biodiesel has been dirty oil. Though our friendly local restaurant is good enough to give us oil that is pretty clean, some of it is less than crystal clear. Leave it a few days to settle, particularly in warm weather, and the bits of fried food and what I assume to be flour sink, leaving a top layer that is clear to the naked eye.

So far I've been pouring that top layer off into our holding tank, from which it is sent through a 5 micron filter. The filter soon clogs up, but as there's no hurry, it can be left to drip through into a drum as slowly as it likes. The end result is a drum of 'clean' oil that can be tipped into the processor and turned into diesel that is good enough to go straight into the car.

However, that leaves a certain amount of oil that never settles. Often it's only a couple of litres in the bottom of a twenty litre drum. Sometimes though, we get given a drum that barely settles out at all. Up to now, the unsettled oil has just been accumulating whilst I've tried to work out what to do with it.

Thanks to Meare Solutions (http://www.mearesolutions.co.uk/) it looks like I've cracked the problem. They sell 32 inch long 'sock filters' which fit neatly inside a tiny space-saver water barrel that was on discount at our local DIY store. The 'sock' can take at least ten litres of dirty oil at a time, allowing the filtered oil to drip into the barrel through the sock wall and leaving a thick layer of 'dry' debris inside the filter. All I need to do is to top it up each morning. By the following day pretty much all of the usable oil has been extracted and the sock can be topped up again. In only a few days I've got through nearly the entire backlog of dirty oil.

The end result is more oil for biodiesel, and conveniently dry waste that can be much more easily disposed of. The only question remaining is how long the socks will last, and whether they can be reused by tipping out the dry waste.

How to Keep Warm in Winter

Here's a little video I've made about the hot air blower we're going to use to keep ourselves warm this winter. It's the first video I've made, so it's rather simple, but I'm pretty pleased with it.



Now that we've sucessfully made biodiesel from the oil we've been collecting, we can use it to run a heater. It's a very sophisticated device, burning the fuel like a little jet engine and using a heat exchanger to warm up nice fresh air. The heater pushes out an enormous volume of hot air and will be connected to warm our bedroom and bathroom. Though it sounds pretty noisy in the video, once it's warmed through it settles down to be much quieter. Adding a silencer and hiding it away under the caravan should let us keep it on throughout the night without disturbing our sleep.

Can you tell what it is yet?

Putting this together has been very, very satisfying. It seems I've not quite grown out of meccano. There are a few more bits and pieces to add yet, but once it's finished it'll be a biodiesel reactor.

Add used chip shop oil and a bucket of chemicals, leave for a few hours and (with some luck) out comes diesel. It should be good enough for running the truck and heating the caravan and will cost quite a bit less than normal diesel. Best of all though, it's carbon neutral - recycled fuel made with recycled plumbing.